Experimental Study on Hydrate Safe Flow in Pipelines under a Swirl Flow System.

With the development of oil and gas resources gradually extending to the deep sea, the blockage of gas hydrate is attracting more and more attention. How to inhibit hydrate blockage efficiently and economically in oil and gas gathering transportation pipelines and ensure the safe operation has become a hot and difficult point in the field of oil and gas gathering and transportation research. At present, the research on the safe flow of gas hydrate is still in the exploratory stage, and applying swirl flow to hydrate risk control technology has a great engineering application value. A systematic experimental study on the safe flow of gas hydrate in a swirl flow system is carried out herein. The experimental results show the following: (1) The laws of gas hydrate flow, transport, deposition, and pipe plugging under various experimental conditions of the swirl flow system are obtained, the safe flow region of hydrate under the swirl flow system in the pipeline is obtained, and the safe flow boundary of hydrate is expanded. (2) Beginning with the theoretical analysis of the safe flow of gas hydrate in a pipeline, the flow characteristics of gas hydrate in the flow system are described; the special flow form of swirl flow has a great influence on the safe flow law of hydrate. (3) The growth and coalescence mechanisms of spiral hydrate in two mainstream systems of separated flow and dispersed flow are explored and researched. The critical tangential velocity of flow is taken as the standard of criterion.